<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>increment</title>
    <style>
        h1{
            counter-increment: aaa;
        }
        h1:before{
            content: counter(aaa)'.';
        }
    </style>
</head>
<body>
<h1>大标题</h1>
<p>文字</p>
<h1>大标题</h1>
<p>文字</p>
<h1>大标题</h1>
<p>文字</p>
</body>
</html>
